This core facility will serve all three projects by providing a center of excellence in molecular biology and biotechnology for the Institute of Parasitic Diseases (IPD). Through common space, large equipment, and trained expertise in applying diverse molecular tools we will greatly augment the molecular systematic medical malacology and parasitology component at the I.P.D. The proposed Core will become the premier Molecular Parasitology and Parasite Biotechnology resource center for all China. Specifically we propose: 1) To study molecular genetics and divergence of targeted populations of parasites and snail hosts using modern techniques in molecular biology and biotechnology. Genetic divergence will be examined through the analysis of genetic markers using allozymes, restriction fragment length polymorphisms (RFLPs), and DNA sequencing of targeted genes. The focus here will be to uncover the degree of genetic convergence and phylogeny among populations of parasites and their snail vectors previously thought to comprise the same species, and by implication, genetically uniform; 2) To catalogue the genetic diversity within the three helminth groups and their snail vectors through the construction of genomic and cDNA libraries; 3) To provide the computer- mediated analytic capabilities to assess the molecular taxonomic data collected in specific aims 1 and 2; 4) To develop novel molecular transfection systems for targeted vaccine delivery.